Executive Functions (EFs) are conceptualized in different, yet overlapping ways in the neuropsychological, cognitive, and educational literatures, and they have a robust relationship to reading comprehension (RC) and other academic skills. Commonalities include the processes necessary for approaching problems, for generating/selecting/implementing strategies relevant to the goal of solving a problem, and for monitoring those processes to alter course if needed. Reflecting these commonalities, EFs are defined here as domain general control processes important for managing goal-directed behavior. Project 2 is designed to clarify the structure of EF, determine the relevance of that structure to RC and other academic skills, and evaluate how EF might most effectively be integrated into remedial RC interventions such as those proposed by Project 3. Aim 1 assesses dimensions of EF (shifting, inhibition, attentional control, fluency, planning, regulatory control, and contextual learning) using latent variables in a large, diverse sample (N=750) of children aged 8 to 12. Interrelationships of EF dimensions, and with non-EF dimensions, are evaluated with RC as a criterion, including comparisons among subgroups of students with difficulty in different academic domains. Aim 2 manipulates key instructional components (similar to those used in Project 3) in conjunction with student EF characteristics in struggling and typical readers. Manipulated components identify what types of instruction are differentially effective (incorporating background knowledge and self-regulation to varying degrees; comparing strategies individually and collectively with self-regulation components). EF characteristics evaluates for whom manipulations might be differentially effective. It is expected that Project 2 will produce a useful framework for guiding research linking EF with RC, elucidating the value-added contribution of EF in the context of known language-based contributions. We have organized Projects 2 and 3 to accelerate the often delayed connection between cognitive processing type studies like those proposed in Project 2 and intervention studies like those proposed in Project 3 by co-designing the studies so that findings can be integrated with the intent of developing more impactful interventions.